The energy industry moved preemptively to shield itself from these changes, too. The Safe Drinking Water Act prohibited the EPA from interfering with the economics of the oil and gas industry unless there was an imminent threat to health or the environment. The industry argued that its waste was mostly harmless brine and that testing and inspecting hundreds of thousands of wells for waste that would qualify as "hazardous" would delay drillers or cost them a fortune.

"It would have been crippling to U.S. oil and gas production," said Lee Fuller, vice president of government relations for the Independent Petroleum Association of America. Fuller was a former staff member for the Senate Environment and Public Works Committee, whose ranking member at the time, the late Texas Sen. Lloyd Bentsen, led the fight against the hazardous waste rule. "So yes, the industry was very aggressively seeking some mechanism to address those consequences."

Bentsen had won the industry a temporary reprieve in 1980 by persuading Congress to redefine any substance that resulted from drilling -- or "producing" -- an oil or gas well as “non-hazardous,” regardless of its chemical makeup, pending EPA study. In 1988, the EPA made it permanent, handing oil and gas companies a landmark exemption. From then on, benzene from the fertilizer industry was considered hazardous, threatening health and underground water supplies; benzene derived from wells for the oil and gas industry was not.

The effect was that the largest waste stream headed for underground injection, that from the oil and gas industry, was exempted from one of the most effective parts of environmental rules governing hazardous waste disposal.

"A blanket exemption without any sense of what the actual chemistry of these wastewaters is, is very concerning," said Briana Mordick, a geologist at the Natural Resources Defense Council.

Other protections also began to unravel, widening the gap between Class 1 and Class 2 well regulations. Both regulators and the industry regularly refer to drilling waste as "salt water" even though, according toa 2002 EPA internal training document obtained by ProPublica, "on any given day, the injectate of a Class II-D well has the potential to contain hazardous concentrations of solvents, acids, and other… hazardous wastes."

Once the wastes were defined as nonhazardous, there was little justification for holding Class 2 wells to the same rules as other waste being injected deep underground.

Today, for example, Class 1 wells for hazardous waste are tested for pressure continuously and are supposed to be inspected for cracks and leaks every 12 months. Oil and gas wells -- though the goal is to inspect their sites annually -- have to be tested only once every five years.

Injection wells are known to cause earthquakes, so Class 1 wells usually have rigorous seismic and geologic siting requirements. Often, Class 2 wells do not. An EPA staff member might spend an entire year reviewing an application for a new hazardous waste well. Class 2 wells are often permitted in bulk, meaning hundreds can be green-lighted in a matter of days.

Where Class 1 hazardous waste is injected, companies have to inspect a two-mile radius for old wells, making sure contaminants will have no avenue to shoot back up into drinking water aquifers or to the surface. The minimum standard for oil and gas companies is to inspect within 400 yards, even though it is widely believed, according to internal EPA memorandums obtained by ProPublica, that such a rule is arbitrarily defined, runs against "much existing evidence" and "may not afford adequate protection" of drinking water.

EPA officials acknowledge that their Class 1 regulations represent the best practices to keep water safe and that the risk of a Class 2 well leaking is no different than the risk of a Class 1 well leaking. The contrast in regulations reflects "varying legal authorities, not varying levels of confidence," an agency spokeswoman wrote in an email, referring to the mandate not to let environmental rules interfere with the nation’s drilling progress.

State injection regulators counter that much drilling-related waste is put in the same geologic formations that produce oil and gas, in which contaminants like benzene naturally occur. The water close to these wells is often already undrinkable, they say, so lesser protections make sense.

According to the EPA’s most recent inventory, the number of Class 2 wells is near an all-time high.

Oklahoma, Texas, Kansas and California use tens of thousands of Class 2 wells to push out oil and gas or dispose of fracking fluids and "produced" water, as the waste derived from drilling is called. In North Dakota, injection permits have increased tenfold, with more wells being permitted in one month – September 2011 –than is typical in an entire year. New Mexico issued twice as many permits last year as it did in 2007. Ohio injected twice as much waste in 2011 as it did in 2006 and is evaluating applications for dozens of new injection sites. largely for waste exported by Pennsylvania and New York, where such wells are deemed unsafe.

As much as 70 percent of the waste destined for Class 2 facilities would be considered toxic if it were not for the loopholes in the law, according to Wilma Subra, a chemist and activist who sits on the board ofSTRONGER, a partnership of oil and gas industry representatives and state regulators aimed at bolstering state standards.

"The law allows it," Tom Tomastik, a geologist with Ohio’s Department of Natural Resources and a national expert on injection well regulation, replied in a Sept. 17 email. "It does not matter what is in it. As long as it comes from the oil and gas field it can be injected."

Well Operators Game Safety Tests

When Carl Weller showed up, shovel in hand, at a Kentucky farm field dotted with injection wells in June 2007, he was acting on a tip. Weller, a contracted EPA injection inspector, was an expert in testing for what regulators call "mechanical integrity," using air pressure to check if wells have leaks or cracks.

Such tests are among the only ways to know whether cement and steel well structures are intact, preventing brine and other chemicals from reaching drinking water.

Using his shovel, Weller dug around the top of a well, unearthing the steel tubing near the surface. A few inches down, he came across an apparatus he had never seen before: A section of high-pressure tubing ran out of the well bore and connected to a three-foot-long section of steel pipe, sealed at both ends. The apparatus appeared designed to divert air pumped into the well into the pipe instead, making the well test as if it were airtight.

"The only reason that I know of that that device would be installed would be to perform a false mechanical integrity test, more than likely because the well itself would not pass," Weller testified in 2009 as part of a case against the well’s operator. The EPA did not make Weller available to comment for this article.

When EPA inspectors kept digging, they found the buried devices on 10 more wells.

The case stunned regulators. Weller had been inspecting the site’s injection wells, which were used to enhance the recovery of oil, for the better part of a decade, certifying them as safe. After the EPA’s discoveries, workers at the company that operated the wells, Roseclare Oil, accused its manager, Daniel Lewis, of having conspired to cheat the tests for much of that time.

In 2009, Lewis was convicted of a felony charge for gaming the safety tests on Roseclare’s wells and was sentenced to 3 years probation and a $5,000 fine. He maintains his innocence, saying the wells were rigged by his father, who ran the company’s local operations until his death, but said such practices were typical in Kentucky’s oil and gas industry. "I’d say it’s pretty common," said Lewis, whose probation was commuted in 2011. "But it’s not something people go around talking about either."

From Lewis’ perspective, injection well operators sometimes have little choice but to try to fool inspectors. Many wells are decades old and were drilled before the current regulations were written. Some are decrepit, their cement aging and cracked. They also can’t be easily -- or cheaply -- repaired.

Lewis, who is now a part-owner of Roseclare and continues to run its operations, said that before wells were due for EPA inspections he would pretest them himself. If one failed, he’d enter problem-solving mode, prepping the site for the EPA’s arrival. Two of his employees testified that he ordered them to fabricate and install the diverters.

"You go and work in it and try to get it to hold and it won’t hold," Lewis said of the wells. "What are you going to do? It’s kind of a 'Don’t ask, don’t tell.'"

Abrahm Lustgarten is a reporter with ProPublica. He is a former staff writer and contributor for Fortune, and has written for Salon, Esquire, the Washington Post and the New York Times since receiving his master's in journalism from Columbia Universi... READ MORE >

To me, the presence of benzene in fracking waste water is a probable indicator that the drillers were using disel fuel in the fracking fluid, which isn't allowed under the Clean Water Act. I wish the EPA and state authorities would enforce that...

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